1. Field of the Invention
The present invention relates to a device for placing an object to be processed in contact with a supercritical fluid, a subcritical fluid or a liquefied gas within a pressure vessel to process the same.
2. Discussion of the Background
A hot isotropic pressure press processing (hereinafter, referred to as xe2x80x9cHIPxe2x80x9d) is the processing which is carried out, when an inconvenience such as pores occurs within a cast article, a sintered article or the like, for the purpose of removing the pores, with respect to the aforesaid articles, and in which the object to be processed is put into a cylindrical pressure vessel interior of which forms a processing chamber, and a pressure gas atmosphere in excess of hundreds of atmospheric pressure in inactive gas such as argon is exposed thereto.
A supercritical gas extraction method applies a specific characteristic of a substantially middle state between gas and liquid having a state in excess of a critical point (a critical temperature, a critical pressure) peculiar to a material (a density is dose to liquid, and a diffusion coefficient and a viscosity are close to gas). There are characteristics that since extraction can be made under the gentle temperature condition, deterioration and decomposition of unstable objects to be processed can be avoided, that there is no possible residue of solvent in the objects to be processed, and that the solvent has a low viscosity and high diffusion properties, and is high in extraction separation speed.
The critical point of a carbon dioxide used as the solvent is pressure of 73 atm, and a temperature of 31xc2x0 C. Therefore, the device constituting the supercritical gas extraction device has to withstand the use at high pressure.
On the other hand, also in the liquefied gas extraction, the liquefied carbon dioxide is, for example, 60 atm at a room temperature of 20xc2x0 C, and the device need likewise be withstand the use at high pressure.
In such a pressure processing device, particularly where a specimen is a solid, it is necessary to open and close a lid of an extraction tank in taking in and out of the specimen to an extraction tank in which a supercritical gas or a liquefied gas comes in contact with the specimen.
The simplification of the closing operation of the lid, and the positive closing properties under the high pressure at the extraction operation (at the pressure processing) are required.
Recently, these pressure processing devices have various uses, and are being applied also to the process for manufacturing semiconductors and electronic parts. That is, typical applied examples include the way of pressure burying for eliminating pores formed in a metal wiring in the HIP processing, and the washing and drying of minute structures of semiconductors and electronic parts as shown in Japanese Patent Application Laid-Open No. Hei 9-232271 in the supercritical processing.
In these uses, particularly a device which is free from occurrence of dust or the like is necessary. For example, in the processing of semiconductors such as a silicon wafer, in a process, the adhesion of large dusts less than 1 micron called particles to an object to be processed impairs soundness of an electronic circuit pattern formed on the wafer surface, thus requiring a device which realizes particle-free in which is free from or hard to produce such dusts as described.
In the pressure processing devices so far proposed, a seal construction of a lid closing part as disclosed in Japanese Patent Application Laid-Open Nos. Hei 3-135402 and 8-141307 Publications has been used for simplifying the closing operation of a lid.
Japanese Patent Application Laid-Open No. Hei 3-135402 discloses a device characterized in that an inner tube of a pressure vessel is inserted into an outer tube of a pressure vessel, a closing means for both the tubes while enabling insertion is provided, and either inner tube or outer tube is slidably moved to take in and out material from an opening part provided in the circumferential part of the inner tube.
Further, Japanese Patent Application Laid-Open No. Hei 8-141307 discloses a device characterized in that filters are secured integrally to an upper lid and a lower lid, respectively, of a pressure vessel.
However, in these devices, a so-called xe2x80x9cshaft seal constructionxe2x80x9d in which an O-ring or the like is mounted on the cylindrical surface which is positive in high pressure seal has been used. However, in the shaft seal construction, since a guide function for registration of shafts resulting from the closing is imparted to a fixing part in which an O-ring is mounted when the lid is opened and closed, worn refuse of the O-ring caused by the sliding movement of the O-ring forms dust.
The present invention has been accomplished in view of the problem noted above, and has its object to provide a pressure processing device which is useful as compared with the conventional devices.
One of specific objects is to provide a pressure processing device capable of carrying out processing which is free from particles.
In the semiconductor industry of an integrating circuit or the like, particularly, the productivity is very important, but in the conventional techniques, the temperature control accuracy and the temperature control reactiveness which are essential to the enhancement of the productivity were difficult to enhance. Accordingly, in the conventional pressure processing device such as a supercritical extraction tank for placing an object to be processed in contact with supercritical gas, a subcritical gas or a liquefied gas to process the same, no consideration has been made to the point of the particle-free, posing a problem that the conventional device fails to deal with the case where processing in the very clean atmosphere such as an integrating circuit is necessary. It is therefore an object of the present invention to provide a pressure processing device capable of enhancing the temperature control accuracy and the temperature control reactiveness which are essential to the enhancement of the productivity.
Further, since the aforementioned shaft seal construction employs the construction to fit the lids, the moving distance when a vessel is opened and closed is long, and it takes time. It is therefore a further object of the present invention to provide a pressure processing device having a lid construction having a lid construction which enables take-in and take-out by a simple method, without employing the fitting construction, and which has positive closing properties and free from occurrence of dust resulting from the closing of the lid.
Incidentally, the conventional extraction tank is generally of the flange type of an autoclave, which requires fastening using many bolts, thus being not efficient. Accordingly, there has been desired an extraction tank.
Devices for carrying out the closing operation of a pressure vessel relatively simply without requiring fastening using a number of bolts proposed so far include, for example, Japanese Patent Application Laid-Open No. Sho 64-7905, Japanese Patent Application Laid-Open No. Hei 3-135402, Japanese Utility Model Publication No. Sho 63-1182, and the like.
Also in both the Japanese Patent Application Laid-Open No. Sho 64-7905 and Japanese Patent Application Laid-Open No. Hei 3-135402, plugs (corresponding to lids) are detachably fitted into upper and lower parts of the pressure vessel, and a crossing pin was made detachable in the state that a through-hole bored in a diametrical direction of the plug and a through-hole bored in a diametrical direction of the pressure vessel are registered in holes.
Therefore, the axial force exerting in the axial direction of the vessel during the pressure processing is borne by the pressure vessel through the crossing pin, and not only the shearing force exerts on the crossing pin but also the bending force or the like exerts thereon, thus posing a problem in positiveness, and posing a problem also in durability.
Further, when the crossing pin is mounted and removed, the detaching resistance becomes excessive unless the registered continuous through-hole is provided, thus posing a problem that the mounting and removing the crossing pin is difficult (unreliable).
On the other hand, in Japanese Utility Model Publication No. Sho 63-1182, the axial force during the HIP processing can be borne by the press frame so that the problems encountered in Japanese Patent Application Laid-Open No. Sho 64-7905 and Japanese Patent Application Laid-Open No. Hei 3-135402 can be overcome, whereas it is necessary to turn or laterally move the press frame, thus posing a problem that an extra space required for moving the press frame is necessary.
It is a further object of the present invention to provide a pressure processing device which enables the take-in and out of an object to be processed from a vessel by a simple method, is positive in closing properties and axial force bearing properties, and is compact in space required for installation.
Further, a pressure processing device as a washing device for washing parts having a superminute construction such as a semiconductor, a micro machine or the like is disclosed in Japanese Patent Application Laid-Open No. Hei 9-232271.
However, in case of the conventional supercritical washing device, particularly a device for washing a semiconductor wafer, wafers can be processed merely one by one for the high pressure vessel. Since it is of a so-called sheet type, there is a problem that the productivity is poor.
It is therefore another object of the present invention to provide a pressure processing device as a washing device capable of providing processing of high productivity.
For achieving the aforementioned objects, the present invention has employed the following technical means. That is, the pressure processing device according to the present invention is to process an object to be processed by a pressure vessel, said pressure vessel comprising a vessel body and an opening and closing member for closeably closing an opening formed in said vessel body, a seal member being provided on the joining surface in which said vessel body comes in contact with the opening and closing member, the non-sliding joining surface which is not slidably moved when the opening and closing member is moved to be opened and closed.
Since the seal member is provided on the non-sliding joining surface, when the opening is closed or opened by the opening and closing member, the seal member is not slidably moved, thus being able to prevent dust from occurrence.
More specifically, there is provided a pressure processing device for placing an object to be processed in contact with a supercritical fluid, a subcritical fluid or a liquefied gas to process the same within a pressure vessel, said pressure vessel comprising a cylinder one end of which is closed and a lid for closing an opening in the other end of the cylinder, said device further comprising a pressing means for pressing the lid in an axial direction of said cylinder with respect to said cylinder, and a seal member between an open end of the cylinder and the opposed end of the lid opposite to the open end of the cylinder.
Another technical means of the present invention is provided with a diaphragm so as to form an airtight space within the pressure vessel, and a heating means is provided within the airtight space formed by said diaphragm.
In still another technical means of the present invention, a fluid introducing passage to the pressure vessel and a fluid discharging passage are individually provided so that they communicate inside and outside, respectively, of said diaphragm.
In another technical means of the present invention, a filter for supplementing superminute particles is provided halfway of the fluid introducing passage to the pressure vessel.
In another technical means of the present invention, a heat insulating layer is provided internally of the pressure vessel so as to airtightly isolate the inside from the outside of the heat insulating layer, a communicating passage for communicating the inside and outside of the heat insulating layer is provided, and a filter for supplementing superminute particles is provided halfway of the communicating passage.
According to still another technical means of the present invention, there is provided a pressure processing device for placing an object to be processed in contact with a supercritical fluid, a subcritical fluid or a liquefied gas to process the same within a pressure vessel, wherein a diaphragm for housing an object to be processed is provided within the pressure vessel, and a fluid introducing passage to the pressure vessel is provided so that the greater part of fluid flowing into the pressure vessel may flow into the diaphragm.
According to another technical means of the present invention, a filter for supplementing superminute particles is provided halfway of the fluid introducing passage to the pressure vessel.
According to still another technical means of the present invention, there is provided a pressure processing device for placing an object to be processed in contact with a supercritical fluid, a subcritical fluid or a liquefied gas to process the same within a pressure vessel, wherein a diaphragm formed of a heat insulating material is provided between an object to be processed and a pressure vessel, and a filter for supplementing superminute particles is provided on the side of said diaphragm into which fluid flows.
According to another technical means of the present invention, said diaphragm is formed of ceramics such as quartz, SiC, Si3N4, Al2O3, at least one out of metals of low heat conductivity, or a combination of said materials.
According to another technical means of the present invention, said filter is made of metal.
Further, the pressure processing device according to the present invention is to process an object to be processed by a pressure vessel, said pressure vessel comprising a cylindrical vessel body, and an opening and closing member for closeably closing an opening formed in one end in an axial direction of said cylindrical vessel body by coming into contact with said end, wherein a ring-like groove is provided in a joining surface of said vessel body and said opening and closing member, a ring-like member is detachably fitted in said ring-like groove, a ring-like groove-outer peripheral side seal member is provided, in said ring-like member, on the outer peripheral side of said ring-like groove fitted, a ring-like joining-surface side seal member is provided in a portion opposite to the other joining surface not formed with the ring-like groove, and the diameter of said groove-outer peripheral side seal member is greater than that of the joining-surface side seal member.
According to the constitution as described above, even if a clearance should occur between the cylindrical vessel body and the opening and closing member, the ring-like member could be pressed against the joining surface by pressure within the pressure vessel. Accordingly, the take-in and out for use can be done by a simple method, the closing properties are positive, and no dust caused by opening and closing of the lid raises.
A transmission ring-like member having a process fluid transmission can be held between said ring-like groove and said ring-like member.
Further, the pressure processing device according to the present invention is to process an object to be processed in a processing space within a pressure vessel, said pressure vessel comprising a vessel body and an opening and closing member for closeably closing an opening formed in said vessel body, wherein a seal member is mounted on the joining interface of said vessel body and said opening and closing member, and a plate having a labyrinth construction for trapping particles by the rugged surface is provided on the said processing space side rather than said seal member.
According to the constitution as described above, even if dust is raised by opening and closing of the opening and closing member, the dust is trapped by the plate having a labyrinth construction, thus being able to prevent the dust from raising.
Further, preferably, a fluid communicating passage for discharging the fluid in the processing space through said opening and closing member is formed on the back of the plate having a labyrinth construction. In this case, the dust trapped can be discharged outside the vessel through the fluid communicating passage. Particularly, preferably, pressure processing is carried out while flowing the fluid.
Further, according to the present invention, there is provided a pressure processing device comprising a processing vessel body having at least an opening for taking in and out an object to be processed, a lid for closing and opening said opening of the processing vessel body, and a press frame having a central space therein, in which upper and lower ends on said processing vessel body side are detachably engaged with upper and lower holding parts in aid central space, and the axial force exerting in the axial direction of the vessel is received by the press frame, characterized in that a pressure receiver for receiving said axial force by the press frame in the opposed part between said lid side and said lower holding part of said press frame is provided movably in a horizontal direction, and a lid elevating means is provided which moves up and down the lid in the axial direction of the vessel in the state that the receiver is isolated from the opposed part to freely dose and open the opening.
By the provision of the constitution as described, the axial force during the pressure processing can be received positively through the upper and lower holding parts; the take-in and out of an object to be processed can be made simply by the elevating operation of the lid elevating means after the pressure receiver has been moved in the horizontal direction and isolated from the opposed part; since the horizontal movement of the pressure receiver is not during the pressure processing, there is present a slight clearance between the lid side, the lower holding part of the press frame and the pressure receiver, which will not be a great resistance to the horizontal movement of the pressure receiver; the closing properties during the pressure processing can be maintained positively; and a smaller space for the horizontal movement of the pressure receiver than that the press frame is turned and laterally moved will suffice.
It is suggested that the press frame be secured to a frame through a rail frame, and the pressure receiver be enabled to be laterally moved on the rail extending on the horizontal surface provide on the rail frame side.
By the provision of the constitution as described, the horizontal movement of the pressure receiver becomes light and positive.
Further, it is suggested that the lid elevating means be positioned on the shaft center of the vessel, and the press frame and the pressure receiver be respectively provided in a pair on the left and right to the shaft center of the vessel.
By the provision of the constitution as described, the vertical movement of the lid is light and positive, and the seal material (such as an O-ring) when the lid is fitted in the opening is less damaged to assure the closing properties during the pressure processing.
Further, in the pressure processing device as a washing device according to the present invention, the following technical means was employed paying attention to the fact that a plurality of objects to be washed may be processed simultaneously for enhancing the productivity.
That is, the pressure processing device according to the present invention is characterized by a device wherein within a washing vessel in which a washing fluid can be flown in and discharged, an object to be washed such as a semiconductor wafer is washed by said washing fluid, wherein a housing vessel for housing a plurality of objects to be washed is provided within said washing vessel, said housing vessel being provided in the plural number with inlets for causing the washing fluid to flow into the housing vessel, and outlets for causing the washing fluid to discharge outside the housing vessel, and opening areas and or opening numbers of said inlets and outlets are different in the direction of placing the objects to be washed so that the quantities of said washing fluid flowing on the surfaces of the objects to be washed are substantially uniform.
According to the aforementioned pressure processing device (washing device), a plurality of objects to be washed can be housed into a high pressure vessel by the housing vessel, and the plurality of objects to be washed can be processed simultaneously.
Here, the flow rate of the washing fluid flown into the washing vessel is not constant in a space within the washing vessel. That is, the flow rate is large near a position in which the washing fluid flows into the washing vessel, while the flow rate is small at a position away therefrom. Sometimes, the flow rate is not even depending on the shape of the space in the washing vessel but a difference occurs depending on the position.
While in the present invention, the inlets and outlets for introducing and discharging the washing fluid into the housing vessel for housing the plurality of objects to be washed are provided, it is noted that the flow rate of the objects to be washed flowing through the inlets and outlets is possibly different every object to be washed. That is, there occurs a difference in the quantity of the washing fluid flowing into the housing vessel from the inlets whereby the objects to be washed are not possibly washed evenly.
Since in the present invention, the opening areas and or opening numbers of said inlets and outlets are different in the direction of placing the objects to be washed so that the quantities of said washing fluid flowing on the surfaces of the objects to be washed are substantially uniform, the washing fluid flows on the surfaces of the objects to be washed substantially evenly to be able to wash the plurality of objects to be washed.
Further, preferably, the inlets and outlets near the position in which the washing fluid flows into the washing vessel are small in the opening area and or opening number, and the inlets and outlets away from the position in which the washing fluid flows into the washing vessel are large in the opening area and or opening number.
As mentioned previously, the flow rate of fluid is large near the position in which the washing fluid flows into the washing vessel, and accordingly, the washing fluid tends to flow from the inlet of the housing vessel. On the other hand, the flow rate of fluid is small away from the position in which the washing fluid flows into the washing vessel, and accordingly, the washing fluid is hard to flow from the inlet of the housing vessel. Taking this into consideration, the opening area and or the opening number are small in the inlets and outlets near the position in which the washing fluid flows into the washing vessel, and the opening area and or the opening number are large in the inlets and outlets away from the position in which the washing fluid flows into the washing vessel whereby the quantities of the washing fluid flowing on the surfaces of the objects to be washed are made even.
Further, preferably, the washing fluid flows from the top and is discharged from the bottom, and a plurality of objects to be washed can be housed in the housing vessel in the vertical direction, and the opening area and or opening number are large in the lower inlets and outlets.
Further, preferably, the washing vessel is internally provided with a guide part for guiding the washing fluid flown in toward the inlet of the housing vessel. Thereby, the washing fluid is supplied into the housing vessel efficiently.
Further, preferably, a unidirectional flowing channel is formed within the washing vessel, in which the washing fluid flown into the washing vessel flows into the housing vessel from the inlet and is discharged outside the housing vessel from the outlet, after which it is discharged outside the washing vessel.
In this case, the washing fluid discharged out of the housing vessel is discharged outside the washing vessel as it is to prevent the contaminated washing fluid for reflowing within the washing vessel.
Further, preferably, a projection for placing and holding an object to be washed is provided in the inner surface of the housing vessel, and a plurality of objects to be washed can be held easily by the projection.
Further, preferably, the housing vessel is constituted from a plurality of divided members divided in the placing direction of an object to w be washed.
In this case, the taking-in and out of the objects to be washed with respect to the housing vessel can be carried out simply.
Further, if it is supposed that the divided members are joined by a hinge, and the housing vessel can be opened and closed by the hinge, the taking-in and out of the objects to be washed with respect to the housing vessel can be carried out more easily by opening and closing the housing vessel through the hinge.
Further, preferably, the washing vessel is provided with a fluid main discharge passage positioned externally of the housing vessel, and a fluid sub-discharge passage positioned internally of the housing vessel.
Not only the fluid main discharge passage but also the fluid sub-discharge passage positioned internally of the housing vessel are provided whereby fine stains (particles) can be prevented from staying in the housing vessel.
Further, preferably, a diaphragm chamber is provided between the washing vessel and the housing vessel. By the provision of the diaphragm chamber, it is possible to prevent fine stains generated from the washing vessel can be prevented from flowing into the housing vessel.
The present invention is characterized, as viewed from the other point, by providing a device wherein within a washing vessel in which a washing fluid can be flown in and discharged, an object to be washed such as a semiconductor wafer is washed by the washing fluid, wherein a housing vessel for housing a plurality of objects to be washed is provide interiorly of the washing vessel, said housing vessel being provided with an inlet for causing a washing fluid to flow into the housing vessel and an outlet for causing the washing fluid to discharge outside the housing vessel, and a first guide passage for guiding the washing fluid flown into the washing vessel to the inlet, and a second guide passage for guiding the washing fluid discharged out of the outlet outside the washing vessel are formed within the washing vessel.
Even by the constitution as described above, a plurality of objects to be washed can be housed into a high pressure vessel by the housing vessel, and a plurality of objects to be washed can be processed simultaneously.
In the construction in which the housing vessel for housing a plurality of objects to be washed is provided, the housing vessel comprising the inlet and the outlet, the first guide passage for guiding the washing fluid flown into the washing vessel to the inlet, and the second guide passage for guiding the washing fluid discharged out of the outlet outside the washing vessel are formed within the washing vessel, whereby the washing fluid discharged out of the outlet and stained is prevented from reflowing within the washing vessel.
More specifically, preferably, a diaphragm chamber is provided between the washing vessel and the housing vessel, the diaphragm chamber being partitioned into a space serving as the first guide passage and a space serving as the second guide passage.
In this case, the first guide passage and the second guide passage can be constituted by the simple constitution, and the fine stains of the washing vessel are prevented from flowing into the housing vessel by the diaphragm chamber.